DE19712622A1 - Arrangement for automatic correction of faulty sensing signals of incremental position measurement devices - Google Patents

Abstract

The arrangement has an evaluation unit with a processor unit (5). A pair of phase-offset analogue sensing signals (S1',S2') are input to the evaluation unit. The sensing signals are characterised by a certain deviation from the ideal signal form. The evaluation unit determines correction parameters using a correction algorithm. The correction parameters are converted into control signals. The sensing signals and the control signals are fed to a correction unit (6). The processor unit and the correction unit are arranged so that sensor signals are input to the processor unit after passing through the correction unit.

Description

The present invention relates to an arrangement and a method for automatic correction of faulty scanning signals according to the Ober Concept of claims 1 and 10. In particular, the fiction appropriate arrangement and the inventive method for use within an incremental position measuring device.

In known incremental position measuring devices result in the Scanning of a periodic scale structure using a suitable usually formed at least two pha on the output side offset periodic, analog scanning signals. These are known in How to determine the relative position of scale division and Processing unit further processed in a downstream evaluation unit. Scanning unit and scale division are approximately two to each other connected movable parts of a machine tool; as an evaluation unit is used for numerical control.

The accuracy of the position determination with the help of such a position onsmeßeinrichtung now depends on the quality of the in this way and  Generated periodic scanning signals. Depending on the phy There are a number of sources of error here of various kinds. For example, optical measuring systems inaccuracies in the reflective or transmissive parts structures negatively affect the signal quality. Also with other Ab probe principles, for example in magnetic position measuring devices, are not always the desired requirements for the resulting Output signals met. For example, the scanning distance can vary or temperature fluctuations the magnetic field sensitive detector affect gate elements etc.

In particular in the case of a subsequent interpolation, that is to say an electro African further subdivision of the analog scanning signals, be tuned types of errors disruptively. The prerequisite for interpolation however, an ideal form of the analog scanning signals or a corresponding one ideal relationship between them. The ver different types of errors by possibly existing different Amplitude values of the two phase-shifted scanning signals by one Phase offset that deviates from the assumed phase offset like any existing DC offsets of the two periodic ones Scanning signals. In the case of conventional incremental measuring systems it is with the mentioned phase shift by 90 °; with interferential three-grid measurement systems can also have an ideal phase shift of 120 ° between three different scanning signals are present.

In addition to the possibility of optimizing the actual signal acquisition, exi approaches such as such errors in position measuring devices, the pe deliver periodic, analog scanning signals, automatically on electronic Way can be corrected. From the publication "Auto correction of interpolation errors in optical encoders "by C. Wang et al. in Proc. of SPIE Vol. 2718, 1996, pp. 439-447 is such an electronic one Correction methods for optical position measuring devices are known. It will proposed here, the analog scanning signals on the one hand nete A / D converter to feed a microcontroller, within it Correction parameters determined on the basis of a known algorithm will. A method is used as the correction algorithm,  the Z. B. in the publications by P.L.M. Heydemann "Determination and correction of quadrature fringe measurement errors in interferometers ", Applied Optics, Vol. 20, No. 3 pp. 3382-3384, 1981 and K.P. Birch, "Optical fringe interpolation with nanometric accuracy ", Precision Engineering, Vol. 12, No. 4, pp. 195-198, 1990. Above the microcontroller downstream D / A converters arrive at the correction parameters analog circuit via which the action on the analog, periodi scanning signals is possible. On the output side, the analogo gene circuit accordingly the corrected scanning signals that the presuppose ideal signal shape and in known off electronic values can be processed further.

One disadvantage of this proposed solution is that that usually also the analog circuit via which to the analog Scanned signals is affected, is associated with certain errors. For this include undesired offset errors or an undefined signal ver Strengthening. These errors are found when determining the correction parameters or the corresponding control signals, however, are not taken into account and falsify accordingly, the analog scanning signals are still undesirable ter way. On the other hand, the sensitivity of the Micro controller generated correction parameters or the corresponding Stellsi gnale to be matched to the analog circuit, which at possibly existing errors in the analog circuit is problematic. Furthermore, it proves to be disadvantageous that the selection of the determinations correction data used in software must be checked. Such a review of the data requires one certain computing time, which in turn is the speed of the proposed limited correction procedure and especially with high travel speeds is important.

The object of the present invention is the known, generic Arrangement or the corresponding method from the above To further develop the publication as advantageously as possible in order to make one more improved correction of the faulty, analog scanning signals of a  ensure incremental position measuring device, d. H. that at Ab to eliminate or at least minimize the resulting errors.

This object is achieved by an arrangement with the features in characterizing part of claim 1 or with the aid of a method, that characterized by the characterizing features of claim 10 becomes.

Advantageous embodiments of the arrangement according to the invention or of the method according to the invention result from the in the dependent measures listed against claims.

According to the invention, a signal correction arrangement is now based proposed a regulation to the different scanning errors eliminate. This means that the output side of the correction unit Analog scanning signals from a Processor unit are supplied based on the supplied Ab again applies the correction algorithm to the scanning signals, corresponding correction variables or analog control signals are determined and this in turn passes to the correction unit, where an action on the analog scanning signals is possible, etc.

As a result, scanning signals that the correction unit already have gone through or have already been corrected as a basis for serve the correction algorithm, a further improved Si results gnal correction. In particular, the problems mentioned above can be solved handle any errors in the analog correction unit. When determining the required correction parameters, such Errors are taken into account and the corresponding control signals are output compensated.

Furthermore, the inventions result in an advantageous embodiment arrangement according to the invention a relatively simple structure with only one A / D converter in the processor unit required on the input side.  

Furthermore, the inventive method and the inventive Arrangement extremely flexible with regard to the choice of those signal values that ultimately used to determine the correction parameters. In particular, there are no complex and computation time intensive Measures regarding the selection of the selected signal values are required such. So with the help of the method according to the invention or with the arrangement according to the invention even at high relative speeds of scale division and scanning unit in a reliable form desired corrections can be made.

The measures according to the invention can all be internal, for example half of the respective position measuring device. Is next to it however, it is also possible to take the appropriate action on others Position, d. H. outside of the actual position measuring device Ren. In both cases, appropriately corrected scanning signals to one Subordinate evaluation unit transmitted and for position determination processed further.

Further advantages and details of the arrangement according to the invention and the method according to the invention result from the following description of an exemplary embodiment with reference to the attached FIG. 1. This is only a schematic representation of a possible embodiment, that is to say within the scope of the measures according to the invention Suitable modifications of this are possible.

Is indicated schematically in Fig. 1 on the left side of a scanning unit 2 with which a scale graduation 1 is scanned. Scale division 1 and scanning unit 2 are, as is to be indicated by the corresponding arrow, displaceable or movable relative to one another. With regard to the signal generation and the specific implementation of scale division 1 and scanning unit 2 , there are many different possibilities. For example, this can also be an optically scanned scale graduation as well as a magnetic graduation structure, which is scanned by means of an appropriately designed scanning unit for generating displacement-dependent scanning signals. In addition, other physical scanning principles for signal generation can of course also be used, such as inductive scanning principles that are operated in conjunction with a carrier frequency evaluation method, etc.

In the case of optical position measuring devices allow the Invention appropriate measures, for example the use of so-called pretensioned Photo elements or photodiodes that have fast response times however, due to their temperature dependency, faulty scanning signals can deliver. With magnetic position measuring devices can also those errors are corrected by using field plates, magnetoresistive elements or Hall elements as a magnetic field sensitive detector elements are caused.

Furthermore, the variant of a length measuring system shown is also to be understood only as an example, d. H. it can of course also be rotary trained measuring systems with the arrangement according to the invention be nated, over which the rotational movement of two mutually movable cher objects to be detected, etc.

On the output side, periodic analog scanning signals S1, S2 are present on the scanning unit 2 of the exemplary embodiment shown, which can be used by a downstream evaluation unit 3 for position determination in a known manner and are interpolated for this purpose, etc. The schematically indicated evaluation unit 3 can be, for example, the numerical control of a machine tool. The evaluation unit 3 presupposes a specific, ideal signal form of the two scanning signals S1, S2 and corresponding relationships between the signals. This includes an ideal phase offset of 90 ° between the two periodic scanning signals S1 and S2, the same signal amplitudes as possible and vanishing DC components or offsets of the signals S1 and S2. In order to meet these requirements of the evaluation unit 3 , certain measures are now provided according to the invention, so that an automatic correction of the normally faulty scanning signals S1, S2 takes place during the measuring operation and such optimized scanning signals S1 ', S2' are passed to the evaluation unit 3 .

The arrangement 4 according to the invention required for this essentially comprises a processor unit 5 and a correction unit 6, which is preferably constructed analogously. The periodic scanning signals S1, S2 supplied by the scanning unit 2 first arrive at the correction unit 6 within the arrangement 4 according to the invention for the automatic correction of the various scanning errors. Via the correction unit 6 , a number of comparison possibilities are given for the faulty scanning signals S1, S2, which are explained below.

On the part of the correction unit 6 , in addition to operational amplifiers 7.1 , 7.2 , 8.1 , 8.2 arranged on the input and output sides , a number of analog adjustment elements 9.1 , 9.2 , 9.3 are provided, via which the analog scanning signals S1, S2 can be influenced in a defined manner . The analog adjustment elements 9.1 , 9.2 , 9.3 are z. B. designed as an electronically adjustable potentiometer, the resistances can be varied via control signals within suitable limits. To correct the various sampling errors, two compensation elements 9.1 , 9.2 are provided in the correction unit 6 , which are each connected between the "-" input of the input-side operational amplifiers 7.1 , 7.2 and their output. A defined variation of the signal amplitudes of the two scanning signals S1, S2 is possible via these adjustment elements 9.1 , 9.2 . As already indicated above, the evaluation unit 3 assumes the same amplitudes of the two analog sampling signals S1, S2 as possible during further processing. Another adjustment element 9.3 is connected between the two processing channels of the scanning signals S1, S2 and allows the defined variation of the phase position of the two scanning signals S1, S2, which are ideally phase-shifted by 90 ° to one another.

The various adjustment elements 9.1 , 9.2 , 9.3 are acted upon by setting signals S _A1 , S _A2 , S _ϕ to set the required values. Further adjustment options for the analog scanning signals S1, S2 exist due to the control signals S _O1 , S _{O2 present} at the "+ U" inputs of the input-side operational amplifiers 7.1 , 7.2 . The DC voltage component or offset of the two scanning signals S1, S2 can be defined via these. With regard to the generation of the various control signals S _A1 , S _A2 , S _O1 , S _O2 , S _ϕ , reference is made to the following description. The embodiment of the analog correction unit 6 shown in FIG. 1 is of course to be understood only as an example and can be modified within the scope of the present invention.

During the measuring operation, the above-described comparison possibilities within the correction unit 6 of the arrangement according to the invention apply the incoming analog scanning signals S1, S2 continuously with certain actuating signals S _A1 , S _A2 , S _O1 , S _O2 , S _ϕ . In this way, the ideal signal form of the originally faulty scanning signals can be established and ideally corrected, corrected scanning signals S1 ', S2' can be transferred to the downstream evaluation unit 3 . The generation of the various actuating signals S _A1 , S _A2 , S _O1 , S _O2 , S _ϕ for the various comparison options takes place according to the invention via the processor unit 5 , to which those scanning signals S1 ', S2' are supplied which are on the output side of the correction unit 6 are on and are to be transferred to the evaluation unit 3 . On the basis of the signals S1 ', S2' present on the input side, the correction units or correction parameters are determined in the processor unit 5 and the corresponding actuating signals S _A1 , S _A2 , S _O1 , S _O2 , S _{ϕ are} generated for the analog scanning signals S1, S2. From the output side, the control signals S _A1 , S _A2 , S _O1 , S _O2 , S _ϕ are consequently present on the processor unit 5 , via which the various signal alignments that may be required are carried out within the correction unit 6 with the previously explained adjustment options, in order to match them Way to ensure the desired ideal waveform of the analog scanning signals S1, S2 running.

In the exemplary embodiment shown, the processor unit 5 comprises two sample / hold stages 10.1 , 10.2 arranged on the input side for the pair of periodic scanning signals S1 ', S2', ie one corresponding stage 10.1 , 10.2 per scanning signal. The two sample / hold stages 10.1 , 10.2 is followed by a multiplex unit 11 , via which the applied analog sampling signals S1, S2 are sequentially switched through to an A / D converter unit 12 . The A / D converter unit 12 digitizes the analog scanning signals S1 ', S2', ie the processing of the scanning signals S1 ', S2' takes place in the processor unit 5 in digital form. The digitized scanning signals are fed to a CPU 13 , which is designed in the form of a microprocessor and which is also assigned a working memory 14 .

In principle, it would also be possible as an alternative to provide several parallel A / D converter units instead of the variant shown with a multiplex unit 11 and an A / D converter unit 12 .

Via the CPU 13 , any necessary correction quantities for the scanning signals S1, S2 are determined by means of a suitable correction algorithm. For this purpose, a plurality of signal value pairs belonging together from the two present scanning signals are preferably stored and, on the basis of a number of such value pairs, the corresponding correction values or the analog actuating signals S _A1 , S _A2 , S _O1 , S _O2 , S _ϕ ge are formed. With regard to an advantageous possibility of determining correction sizes for phase-shifted scanning signals of a position measuring device which are afflicted with scanning errors, reference is made at this point in particular to the publications by C. Wang et al., PLM Heydemann and KP Birch already mentioned above.

On the basis of the correction algorithm, the CPU 13 determines correcting variables and corresponding actuating signals for the various adjustment options in the correction unit 6 , which are still in digital form at this point. In addition to the determination of correction variables, the central CPU 13 also takes over the complete sequence control and synchronization within the processor unit 6 , which on the one hand and the various components 10.1 , 10.2 , 11 , 12 , 15 a via the corresponding connections between the CPU 13 and the associated memory unit 14 - 15 e of the processor unit 5 is to be indicated on the other hand.

Via a plurality of D / A converter units 15 a, 15 b, 15 c, 15 d, 15 e arranged on the output side in the processor unit 5 , the specific actuating signals still present in digital form are converted into analog output signals S _A1 , S _A2 , S _O1 , S _O2 , S _ϕ , converted and passed to the correction unit 6 . Of course, alternatively, only a single D / A converter unit could be used at this point. Due to the action of the control signals S _A1 , S _A2 , S _O1 , S _O2 , S _ϕ on the various adjustment possibilities of the correction unit 6 , an automatic correction of the periodic scanning signals S1, S2 can take place during the measuring operation. The corrected scanning signals S1 ', S2' are transferred to the downstream evaluation unit 3 .

When the control signals S _A1 , S _A2 , S _O1 , S _O2 , S _{ϕ act} on the analog scanning signals S1, S2, it is also ensured that the correction parameters or control signals S _A1 , S _A2 , S _O1 , Do not change S _O2 , S _ϕ too suddenly. Rather, a certain continuity of the control signals S _A1 , S _A2 , S _O1 , S _O2 , S _{ϕ is} also guaranteed over several correction cycles in order to avoid sudden changes in the output, corrected scanning signals S1 ', S2'. In order to ensure such activity of the control signals S _A1 , S _A2 , S _O1 , S _O2 , S _{ϕ transferred} from the processor unit 5 to the correction unit 6 , there are several possibilities. For example, a maximum, permitted change of the control signals S _A1 , S _A2 , S _O1 , S _O2 , S _ϕ from correction cycle to correction cycle can be specified. Furthermore, the control described can be designed as a PI control, so that the change in the control signals S _A1 , S _A2 , S _O1 , S _O2 , S _{über is} ensured via the integral part of the control.

In contrast to the known prior art, in the arrangement according to the invention, the error-prone, analog scanning signals S1, S2 are only picked up after passing through the correction unit 6 and transferred to the processor unit 5 , which signals the correspondingly required signals S _A1 , S _A2 , S _O1 , S _O2 , S _{ϕ determined} for the different adjustment options in the correction unit 6 . In the subsequent correction cycle, the following periodic scanning signals can already be acted upon with the specific correction or manipulated variables and thus at least roughly corrected. The scanning signals S1, S2, roughly corrected for the first time in this way, then in turn serve as input variables for the processor unit 5 , which, on this basis, redetermine any necessary control signals S _A1 , S _A2 , S _O1 , S _O2 , S _ϕ can make where the subsequent analog scanning signals S1, S2 are applied, etc.. This results in a further improved signal correction of the scanning signals S1, S2, which can be further processed by the downstream evaluation unit 3 . In addition, those errors which are caused by the analog correction unit 6 are also taken into account when determining the various correction variables or control signals S _A1 , S _A2 , S _O1 , S _O2 , S _ϕ .

To carry out the correction algorithm and determine the required Chen correction values or control signals are from the analog scanning signals S1, S2 according to the invention only certain signal-value pairs used. Based on the selected signal-value pairs then the correction algorithm is executed. Here exist with regard to Selection of the signal values used a number of ways within the arrangement according to the invention or within the inventions method according to the invention.

For example, in a first embodiment it is possible to also supply the analog scanning signals S1, S2 in an uncorrected or already corrected form to an interpolator unit which divides the signal period into a predetermined number of counting steps. In Fig. 1 the variant of the selection of the signal-value pairs with respect illustrated in which are tapped at a point of the interpolator supplied signals, signals on after the first correction cycle already corrected sample S1 'S2,'available; with the reference numeral 16 , the inter polator unit is designated, which is designed in a conventional manner. The CPU 13 is then fed in the processor unit 5 via the sample / hold stages 10.1 , 10.2 , multiplex unit 11 and the D / A converter unit 12 only the signal values of the corrected scanning signals S1 ', S2' specified by the interpolator unit 16 at those positions that correspond to the corresponding interpolation counting steps. For this purpose, the scanning signals S1 ', S2' are present on the input side of the interpolator unit 16 ; On the output side, the interpolator unit 16 supplies a corresponding synchronization signal for the CPU 13 , which then causes the signal values to be read in at these positions. To read or capture the signals, at least corresponding signals are in turn passed to the A / D converter unit 12 by the CPU.

As an alternative to this embodiment, it could also be provided that the interpolator unit 16 at the desired positions at which signal values are to be taken over, corresponding synchronization signals to the sample / hold stages 10.1 , 10.2 , the multiplex unit 11 and the A / D converter unit 12 are passed to initiate the reading process into the CPU 13 .

There are a number of possibilities with regard to the design of the interpolator unit 16 . Basically, a further subdivision of the signal period takes place via the interpolator unit 16 and thus the determination of defined positions at which signal values are to be transferred to the CPU for the correction algorithm. For example, about a 10-fold, uniform division of the signal period, so that at a total of 10 interpolation positions, synchronization signals are transmitted for reading in the corresponding signal-value pairs to the CPU 13 . The signal values which are detected or digitized at the corresponding 10 positions are then supplied to the CPU 13 as signal values for the correction algorithm.

For this purpose, in a first embodiment of the interpolator unit 16, the transfer positions can be transferred to the CPU 13 in an absolutely coded form. The synchronization signals therefore consist of the absolute position information at the transfer positions. It has proven to be advantageous that the CPU 13 is immediately aware of the uniformity of the distribution of the received signal values over the signal period due to the known absolute takeover position. It is therefore not necessary to carry out a complex, time-consuming check of the signal values to determine whether these are also sufficiently evenly distributed and are suitable for the correction algorithm.

In a further embodiment, the interpolator unit 16 can make a incremental subdivision of the signal period and, via a counter that is running, determines the respective absolute transfer position that is transferred to the CPU 13 .

Furthermore, it is finally possible in a third embodiment that the interpolator unit 16 only carries out an incremental subdivision of the signal period and transfers corresponding signals for taking over the signal values at several equidistantly distributed positions to the CPU.

In particular in the case of detected higher travel speeds, the transfer of the absolute takeover position from the interpolator unit 16 to the CPU 13 according to the first two embodiment variants proves to be advantageous. In this way it can be ensured that the signal-value pairs are in any case taken over at different positions of the associated Lissajous figure and that the signal values are not always taken over at several positions in succession at the same position in the Lissajous figure.

In addition, it is possible in further embodiments to carry out the selection of signal-value pairs by using software CPU 13 to generate or generate synchronization signals or trigger pulses for sample / hold stages 10.1 , 10.2 , multiplex unit 11 and D / A converter unit 12 be specified. Again, not all analog scanning signals are digitized, but only a certain selection of signal-value pairs at certain positions.

Here, on the one hand, a time-equidistant distribution of triggerim pulses can be specified. To ensure that the corrective signal algorithm pairs used evenly over the associated Lissajous figure are distributed, are suitable for this purpose Signal value pairs or points in time for acquiring the signal value pairs predefined by software.

In the case of possible high travel speeds, however, how which is the case that always occurs over several signal periods Signal-value pairs are detected that are in similar positions on the Lissajous figure and therefore the different signal values pairs are not particularly good as input data of the correction algorithm are suitable. It proves to be advantageous if the current Ver Driving speed, for example, based on the measured values recorded so far is determined. In the case of high travel speeds, the temporal Distribution of the trigger pulses is then changed appropriately to make this case close and as even a distribution of the signal values as possible to ensure pairs for the correction algorithm via the Lissajous figure most.

However, the latter measure need not be taken if one does not have an extremely exact signal element at high travel speeds rectification, but in this case also with inaccurately corrected Ab touch signals on the side of the evaluation unit.

On the other hand, it is also possible to use the trigger pulses for the selection of the In principle, signal-value pairs should not be specified at equidistant intervals, son to specify this as a non-periodic sequence. Here is the temporal Distribution of the sequence of trigger pulses to be chosen so that each is possible traversing speed, an even distribution of the signal Value pairs over the Lissajous figure is guaranteed. For example a suitable statistical temporal distribution of the trigger pulses to the be specified via the CPU.  

In a further embodiment of the arrangement or the method according to the invention can be provided, always in Ab dependence of the relative speed between scale division and scanning Unit to select the signal-value pairs to be used for correction For this purpose, it is generally necessary to use the relative to detect speed, for example, what about suitable detectors or the detection of the frequency of the scanning signals can take place. So can then at slow travel speeds and increased accuracy for example, more signal values from the pair of Sampling signals are used, while at higher Relativge speeds and correspondingly lower precision requirements the signal correction based on fewer signal values is sufficient. In particular In the case of slow travel speeds, many signal Value pairs from the scanning signals are used, via the how for which an averaging is possible. Overall, one of the results like averaging over many signal-value pairs an accuracy for the be agreed correction values above the resolution of the A / D converter unit lies.

In an advantageous embodiment of the arrangement according to the invention or of the method according to the invention, this further comprises a - non-volatile - storage unit in which correction values are stored can. At the beginning of a new measurement, these correction values are in appropriate control signals converted and act on the cor rectification unit the analog scanning signals to be corrected. In this manner and way is already at the first pass of analog scanning signals len by the correction unit a first, at least rough signal correction performed; then the signal correction is carried out by ana lied scanning signals based on the described control as before wrote.

In addition to the exemplary embodiment described, there are therefore one A number of further possibilities, the arrangement or  

the method according to the invention depending on the respective requirement suitable designs.

Claims (17)

1. Arrangement for the automatic correction of erroneous scanning signals of incremental position measuring devices, with at least at the input side at least a pair of phase-shifted, analog scanning signals which are subject to certain deviations from the ideal signal form, an ideal signal form being required by a subordinate evaluation unit

• a processor unit to which the scanning signals are fed and in which correction variables are determined by means of a correction algorithm, which in turn are converted into corresponding actuating signals,
• a correction unit to which the analog scanning signals and the actuating signals are fed and which comprises a plurality of comparison possibilities in order to correct the defective scanning signals by applying the actuating signals,

characterized in that the processor unit ( 5 ) and the correction unit ( 6 ) are arranged such that scanning signals (S1 ', S2') which have already passed the correction unit ( 6 ) are present on the input side of the processor unit ( 5 ). 2. Arrangement according to claim 1, characterized in that at least one A / D converter unit ( 12 ) is arranged on the input side in the processor unit ( 5 ) via which the analog scanning signals (S1 ', S2') can be di gitalized. 3. Arrangement according to claim 2, characterized in that an A / D converter unit ( 12 ) upstream of at least two sample / hold stages ( 10.1 , 10.2 ) and each of these sample / hold stages ( 10.1 , 10.2 ) egg nes Scanning signals (S1 ', S2') is supplied. 4. Arrangement according to claim 3, characterized in that a multiplex unit ( 11 ) is arranged between the A / D converter unit ( 12 ) and the at least two sample / hold stages ( 10.1 , 10.2 ), which a time-sequential switching of the scanning signals ( S1 ', S2') from the sample / hold stages ( 10.1 , 10.2 ) to the A / D converter unit ( 12 ). 5. Arrangement according to claim 1, characterized in that the processor unit ( 5 ) comprises at least one CPU ( 13 ) in the form of a microprocessor with a main memory ( 14 ) which ler unit from the A / D converter ( 12 ) digitized scanning signals (S1 ', S2') are supplied. 6. Arrangement according to claim 1, characterized in that in the pro processor unit ( 5 ) on the output side at least one D / A converter unit ( 15 a, 15 b, 15 c, 15 d, 15 e) is arranged, via which the CPU ( 13 ) certain control signals (S _A1 , S _A2 , S _O1 , S _O2 , S _ϕ ) are passed to the correction unit ( 6 ) in analog form. 7. Arrangement according to claim 1, characterized in that the correction unit Cor ( 6 ) adjustment options for the amplitudes of the analog scanning signals (S1 ', S2'), for the DC components of the analog scanning signals (S1 ', S2') and for the mutual phase shift of the analog scanning signals (S1 ', S2'), which can be acted upon by the processor unit ( 5 ) via the control signals (S _A1 , S _A2 , S _O1 , S _O2 , S _ϕ ). 8. Arrangement according to claim 1, characterized in that the equalization options are at least partially designed as electronically adjustable potentiometers ( 9.1 , 9.2 , 9.3 ). 9. Arrangement according to claim 2 and 5, characterized by an inter polator unit ( 16 ) which divides the signal period of the corrected or uncorrected analog scanning signals (S1, S2, S1 ', S2') into a predetermined number of interpolation positions and at the interpolati positions synchronization signals for reading the associated signal-value pairs into the CPU ( 13 ) can be transmitted. 10. The arrangement according to claim 9, characterized in that the inter polator unit ( 16 ) is designed such that an absolute determination of the takeover position of the signal-value pairs is possible and the absolute position information can be transmitted to the CPU ( 13 ) as a synchronization signal. 11. Method for the automatic correction of faulty scanning signals of incremental position measuring devices which are subject to certain deviations from the ideal signal form, which are required by an ordered evaluation unit, whereby

• the scanning signals are fed to a processor unit and correction variables are determined by means of a correction algorithm, which in turn are converted into corresponding control signals,
• - The analog scanning signals and the control signals are also fed to a correction unit, which comprises a plurality of comparison possibilities, in order to correct the error-prone scanning signals by the application of the control signals, characterized in that

the scanning signals (S1 ', S2') fed to the processor unit ( 5 ) are tapped at the output of the correction unit ( 6 ) and, based on these scanning signals (S1 ', S2'), the actuating signals (S _A1 , S _A2 , S _O1 , S _O2 , S _ϕ ) can be determined. 12. The method according to claim 11, characterized in that a pair phase-shifted scanning signals (S1 ', S2') with respect to the signal ampli tuden, the DC voltage components and their relative phase position kor be rigged. 13. The method according to claim 11, characterized in that per signal period of the scanning signals (S1 ', S2') a predetermined number of Signal values are used to determine the correction variables. 14. The method according to claim 11, characterized in that the scanning signals (S1 ', S2') in the processor unit ( 5 ) are each fed to a sample / hold stage ( 10.1 , 10.2 ), then via a multiplex unit ( 11 ) sequentially switched through to an A / D converter unit ( 12 ) and supplied by this to a CPU ( 13 ) with an associated working memory ( 14 ), via which the correction algorithm for determining the control signals (S _A1 , S _A2 , S _O1 , S _O2 , S _ϕ ) is carried out. 15. The method according to claim 11, characterized in that the corrected in the correction algorithm for determining the correction variables and control signals (S _A1 , S _A2 , S _O1 , S _O2 , S _ϕ ) used signal-value pairs speed-dependent from the analog scanning signals (S1 ' , S2 ') can be selected. 16. The method according to claim 11, characterized in that the control signals acting on the analog scanning signals (S1 ', S2') (S _A1 , S _A2 , S _O1 , S _O2 , S _ϕ ) are selected such that the control signals of successive correction cycles differ by no more than a predetermined amount. 17. The method according to claim 11, characterized in that the signal period of the corrected or uncorrected analog scanning signals is divided into a predetermined number of interpolation positions via an interpolator unit ( 16 ) and the associated signal-value pairs as input values for the respective interpolation positions Correction algorithm can be detected.